The present invention relates to a bus bar used to connect a terminal box and a circuit breaker to each other.
Generally, a bus bar is a metallic bar with screw holes formed at respective ends and is used to connect a power terminal of a terminal box to a power terminal of a circuit breaker.
In order to insulate the terminals from each other, an elevated insulating block is disposed between the terminal box and the circuit breaker. Since conventional bus bars are made of metal, it is inconvenient to install bus bars because conventional bus bars have no safe portion to hold.
Furthermore, since a terminal box is usually electrically live, it is dangerous to hold a bus bar when installing the bus bar. However, in common practices, operators connect a terminal box to a circuit breaker when the terminal box is being supplied with power, i.e. without shutting off the terminal box, for the reasons that it is convenient and simple to operate on connection of the bus bar to the terminal box and the circuit breaker.
Since a metallic connection portion of the bus bar which connects the terminal box and the circuit breaker to each other appears on the outside and thus is contactable after the bus bar is installed. Therefore, there is always risk of short circuiting or electrical shock attributable to changes in surrounding conditions or unexpected accidents.
In order to prevent this, generally an external casing of a terminal box is locked using a lock. Even in this case, the problem that the metallic connection portion is not sealed and insulated within the external casing, is not addressed.
On the other hand, a conventional bus bar functions only as a connection medium to connect power terminals, and it is difficult to use the conventional bus bar for other purposes.
Typically, power lines connected to a terminal box have four lines for four phases of power including a neutral phase. On the other hand, with respect to loads connected to a circuit breaker, there are various types of loads, such as loads using two phases of power and loads using three phases of power. And in terms of the quality of loads connected to each phase of power, the conventional bus bar cannot confirm the differences between the phases of power in phase of reactive power, according to loads such as a load including many inductive components and a load including many capacitive components.
In order to monitor use of power within a terminal box or a circuit breaker, an apparatus in which a power monitoring device is built in a terminal box or a circuit breaker has been already developed. This technology has a problem that an existing terminal box or circuit breaker has to be replaced with this apparatus, resulting in burdensome costs and effort.